Indirectly-heated steam generator



Nov. 18, 1930. H. PEPERKORN 1,781,764

INDIRECTLY HEATED STEAM GENERATOR Filed Dec. 31, 1928 3 Sneets-Sheet 1 Fig. 1.

Nov. 18, 1930. PE ERKGRN' 1,781,764

VINDIRECTIJY HEATED STEAM GENERATOR Filed use. 31, 1928 3 Sheets-Sheet 2 Fig. 3.

1930-, H. PEPERKORN 1,781,764

- INDIRECTLY HEATED STE'AM GENERATOR Filed Dad. 51, 1929 a Sheets-Sheet s Patented Nov. 18, 1930 UNITED. STATES PATENT orr cs HEINRICH PEPERKORN, OF CASSEIEWILHELMSHOHE, GERMANY, A SSIGNOR '10 SCHMIDTSCHE HEISSDAMPF-G-ESELLSCHAFT M. B. H., 01: GASSEL-WILHELMSHOHE, GERMANY, A CORPORATION OF GERMANY INDIRE CTLY-HEATED STEAM. GENERATOR Application filed December 31, 1928, Serial No. 329,640, and in Germany January 5, 1928.

My invention relates to indirectly heated high pressure steam generators with heating elements located within the boiler drum. Steam of higher temperature than that of the working steam is introduced into these heating'elements as ameans for evaporating the water contained in the boiler drum. The said heating steam enters a heating element at its one end, flows through it to its other end and returns to the first mentioned end where it leaves the element in the form of conden-' sate having been transformed into condensate during its passage. through the element. Heating elements of thiskind have been constructed in such a manner that the heating steam and the condensate are led through straight tubes connecting inlet and outlet chambers disposed atone end of'the element with a return chamber disposed at the other end of the heating element.

The object of my invention is to improve .such heating elements and the invention consists therein that in each heating element the two groups of tubes, i. e. the group leading the live heating steam and the group of return tubes leading the condensate and a mixture of steam and condensate are arranged side by side and in such a way that the tubes of these two groups are crossing one another. By this means a heating elementof relatively small height is produced which contains a large heating surface in a given space. Both groups have a positive head in the direction of flow and the ratio between the cross sections and the speeds in the two groups can be properly chosen by givingea corresponding number of tlibes to each group.

A further object of my invention is to provide a special arrangement of the connections of the heating element passing from the body of the header through the wall of the drum which arrangement is of advantage for the introduction of the element-into and its withdrawal from the drum.

, ments of the improved heating element.

In said drawings Figure 1 is a vertical 1ongitudinal section and Figure 2 ahori zontal section of a part of the indirectly heated boiler drum; Figure 3 1s a cross section on line 3-3 and Figure4 a cross section on line 4-4 element in an intermediate position during its withdrawal through the manhole of the drum.

Referring to the drawings 1 indicates the boiler drum in which high-pressure steam is generated by indirectly heating the water contained therein.

' In the example shown three heating elements are disposed in each half of the drum.

Each'heating element has a header 3, divided by a partition wall 4 (Figures 2 and 6) in two chambers 5 and 7. The chamber 7 is provided with, a steam inlet connection 8, the chamber 7 is provided with a condensate outlet connection 6; the connections 6 and 8 passing from the body of the header through the drum wall. A return header 10 at the other end of the heating element is slidably disposed upon a support 9. The

headers 3 and 10 are connected by two groups of straight tubes. The one (larger) group connecting the chamber 5 of the header 3 with the header 10 extends over the whole height of the headers and is composed of tubes 11, whereas the tubes 12, of which the other (smaller) group. is composed lead only from the upper part of the chamber 7 of the header 3 (Figure 6) to a side part of the header 10, this side part be-' ing lower than the principal part of the header 10.

The heating steam enterin the chamber 7 of the header 3 is therefore owing through a group of tubes downward into the return header 10, and the condensate or the mixture out of steam and condensate is likewise flowing downward through a group of tubes from the return header 10 into the chamber 5 of the header 3. In the return header 10 the condensate formed in the tubes 12 is separated from the steam, thiscondensate flowing off through the bottom rows of tubes 11. V The steam entering the return tubes 11 is therefore relatively dry, which is favourable for the transfer of heat from the heating steam to the water 'of the drum.

As shownin Figure 4 the central heating element has the inlet and outlet connections disposed at its lower side and passing vertically 'downward through the wall of the drum whereas the lateral elements have these connections disposed at a corner and passing obliquely through the wall of the drum. Or in the lateral elements the inlet and outlet connections 8 and 6 can be dis osed at the side ofthe header as shown in igure 5 and can pass horizontally through the wall of the drum. In the latter case the header.

containing the inlet and outlet chambers is not built in one piece but the inlet chamber 17 and the outlet chamber 18 are built as separate pieces and secured together by .a. screw 14. This screw has its seat in the one piece and passes through a. slot in the other piece so that the two pieces and the tubes heating steam enters connected with them are allowed to expand freely. a

The embodiments shown are, only examples and may be modified without departing from the nature of my invention. As shown the group of returning tubes contains more tubes than the group of tubes into which the first. In most cases this arrangement will give the velocities best suited for the transfer of heat. But in each case the number of tubes in the two groups of a heating element will have to be chosen according to the special requirements.

For the introduction of the heating element into and its removal from the drum it is essential that the headers together with their connections can be passed through a manhole having no excessive dimensions. With this object in view my invention provides that the connections of the header are so disposed with respect to the body ofthe header and in the direction of the axis of the drum, that the connections and the body of the header can be passed through the manhole one after the other. When removing an element at first the connection "8and the connection 6 t rough the manhole 19. W en doing so the element has to be lifted so high that the under surface 20- of the d n can over the under rim of the manhole 19. Thereupon the element is lowered into the osit-ion shown in Figure 8, in which position to the distance between the'under surface 20 of the connection and the upper edge of the body of the header. The stepped d1sposition of the connections with respect to the body of the header according to my invention affords the advantage that heating ele- ,ments with comparatively large bodies can Iclaim: W

1. In an indirectly heated steam generator the combination of a boiler drum with heating elements disposed within the drum, a

other end, a group of tubes connecting the said inlet chamber with the return header, I

a second group of tubes connecting the return header with said outlet chamber, the said two groups of tubes being arranged side by side and crossing one another.

2. In an indirectly heatedsteam generator the. combination of a boiler drum with heating elements, disposed within the drum, comprlsing headers, tubes connecting the headers, and inlet and outlet connections passing from one of the headers through the drum wall, the said connections and the body of the header being in stepped relation in the direction of the axis of the drum, said drum being provided with a manhole at one end through which the heating elements are adapted to-be inserted, the diameter of said manhole being less than the over all height of the said inlet and outlet connections and the header to which they are connected. I In testimony whereof I haveaflixed my signature.

I HEINRICH PEPERKORN.

it is possible to pass the body. of the header through the manhole. If the connections and the body of the header were not arranged in thisstepped relation the height of the manhole would-have to correspond 

